Method and composition for improving milling products



Patented May 16, 1939 PATENT- OFFICE METHOD AND COMPOSITION FORIMPROVING MILLING PRODUCTS Frederic HfPenn, Dallas, Tex.

No Drawing. Application December 13, 1938, Serial No. 245,504

10 Claims.

My invention relates to the improvement of wheat flour and other millingproducts, including the baking and keeping qualities thereof, and moreparticularly has reference to a method and a composition for thesimultaneous bleaching and ageing or maturing of flour and the like.This application is a continuation-impart of my earlier applicationSerial #227,016, filed August 26, 1938.

According to present commercial practice, flour is bleached and aged inseparate stages of treatment. The ageing is accomplished by treatmentwith a gaseous maturing agent, such as nitrogen trichloride, and thebleaching by mixing with the flour certain powdered organic peroxides,notably benzoyl peroxide. While the last-mentioned step is relativelysimple, the gas treatment is quite cumbersome, requiring specialcontacting apparatus and corrosion-resistant go equipment and accuratecontrol over the gas which presents many hazards and difiiculties inuse.

It is an object of this invention to bleach and age flour and the likein a single operation and 5 to provide a finely divided or powderedcomposition which, when intimately mixed with the flour, functions toefiect a simultaneous bleaching and ageing of the milling product. Theflour is thus improved in the two respects mentioned by the sosimpleexpedient of mixing the solid composition therewith and allowingsufficient time for the desired efiects to take place.

The solid bleaching and ageing composition of my invention comprises apro-formed mixture 35 of a. bromate and an active organic peroxide, thatis, an organic peroxide which is suificiently active in powdered form toeffect at least a 90% flour bleach. I have found that only certainaromatic and fatty acid peroxides are sufficiently so active tocooperate with the bromates to effect the simultaneous bleaching andmaturing of dry fiour or other milling product.

It has heretofore been proposed to treat flour with hydrogen peroxideand other inorganic per- 45 oxides and also certain inactive organicperoxides, such as acetone peroxide, and urea peroxide, in combinationwith various oxidizing agents, including bromates. However, theseinorganic and inactive organic peroxides are not suitable 50 in thepresent invention since they do not function with the bromates tosimultaneously bleach and age flour and the like.

Benzoyl peroxide is the preferred aromatic peroxide of my invention.Cinnamyl peroxide 55 and phenyl acetyl peroxide are other aromaticperoxides which I have found to be of sumcient activity and flourbleaching power for use with a bromate in accordance with the invention.Suitable active fatty acid peroxides of sufficient bleaching power formy purpose are stearyl peroxide, lauryl peroxide and palmitic acidperoxide. However, not all aromatic and fatty acid peroxides areoperative in my invention; for example, phthalyl peroxide is inadequatein activity and bleaching power for use with the bromate.

Potassium bromate is the preferred reagent for use with the activearomatic or fatty acid peroxide but other bromates are, of course,suitable, particularly the bromates of the alkali metals and alkalineearth metals such as sodium, calcium, etc.

Although bromates have heretofore been used as dough maturing agents, itis believed to be fairly well recognized in the art that they have noappreciable maturing action when used in solid form upon dry flour whichhas been bleached or treated with active organic peroxides or otherbleaching agents. However, I have found that the bromates, in finelydivided or powdered form and when employed in admixture with an activearomatic or fatty acid peroxide, function with the peroxide to bringabout a commercially satisfactory maturing and bleaching of dry flour.*Notwithstanding the known use of bromates as dough maturing agents, asfar as I am aware, it was not heretofore recognized that the bromates,in solid form, would operate to mature dryilour simultaneously with thebleaching thereof by means of an active aromatic or fatty acid peroxide.Nor was it appreciated that this ageing with a powdered bromate could beaccomplished without impairment of the bleaching action of the peroxide.

Although I do not wish to limit the invention to any particulartheory'of operation, I believe that the highly active peroxides employedin the composition of my invention function as activators oraccelerators for the bromates, in addition to bleachingthe flour. Thistheory seems to explain why the br'omates in solid form mature the dryflour when used simultaneously or in admixture with the active aromaticand fatty acid peroxides whereas they have no noticeable maturing actionwhen applied to flour which has previously been bleached by means of theperoxide. I believe that I am the first to recognize this phenomenonrespecting the eflicient functioning of powdered bromates as maturingagents active aromatic and fatty acid peroxides.

I am aware that sodium chlorate has heretofore been mentioned as anactivator for certain organic peroxides. and that the chlorates havebeen grouped with the bromates as suitable oxidining agents in thetreatment of animal and vegetable matter,-including flour. However, thechlorates are not the equivalent of the bromates of my invention since,as shown by the experimental data hereinafter included, sodium chlorate,in combination with benzoyl peroxide, was found to have no maturingaction.

The bleaching and ageing composition of this invention is an improvementon the hypochlorite composition of my prior Patent 112,087,547 which isnot stable in the presence of air and hence must be handled in closedequipment to avoid reaction and other inconveniences incident to the useof chlorine. The present composition is not open to these objections. Itis stable under all ordinary milling conditions and is non-corrosive.

In practicing the method of this invention, the bleaching and ageingcomposition is fed directly into the flour at any convenient pointduring the milling operation and intimately mixed therewith, by means ofpowder feeding machines now used in the mills, in the proportion ofabout one-half ounce'to 196 pounds of flour. For thorough distributionof such small amounts of the composition in the flour, the compositionshould be in the form of a dry, free-flowing powder. A satisfactorybleaching and ageing is obtained by exposure of the flour to the actionof the composition for about 24 hours.

As illustrative of the preparation of a preferred composition, drypowdered commercial grade dicalcium phosphate or other suitable carrieris added to an equal weight of dry commercial grade granular benzoylperoxide and the mixture ground to the desired fineness. A fineness ofabout 85% through a 300 mesh sieve is' satisfactory. With the powderthus obtained there is now mixed commercial grade dry powdered potassiumbromate in the proportion of six parts bromate to 90 parts of theperoxidephosphate mixture. The resultant mixture is then ready for useas a. fiour bleaching and ageing composition in the manner alreadydescribed.

Since there are many grades of flour, the proportion of peroxide,bromate, and carrier, as well as the amount of thecomposition requiredfor eif'ective bleaching and ageing, should be determined by test ineach particular case. In some instances, for certain kinds of flour, theproportion of bromate may be increased to as much as 12 parts of thebromate to 90 parts of the peroxide-phosphate mixture. Ordinarily theproportion of 6 parts potassium bromate with 90 parts of the mixture ofequal weights of benzoyl peroxide and dicalcium phosphate issatisfactory for many of the various grades of flour. The

proportions here stated are, of. course, by weight.

The composition of this invention improves the baking qualities of flourto a greater extent than has heretofore been accomplished to my,lmowle'dge. Loaf volume is one of the best indi- -i:ators fordetermining the value of the baking "qualities of flour. The volume ofthe baked loaf of bread is measured in cubic centimeters and denotes theexact size of the loaf produced. Small volume, as obtained withuntreated or unmatured flour, indicates low baking strength while largevolume indicates high baking in dry flour by virtue of their admixturewith the strength which is apparently brought about by the maturing ofthe flour.

The following tabulations show, by comparison, the advantages andsuperiority of my composition over present practice in the art. Table Ideals with a blend of hard and soft wheat flour and Table II with hardwheat baker flour. The tables show the amounts of benzoyl peroxide andpotassium bromate used in the tests. In each case where benzoyl peroxidewas employed, it was mixed with an equal weight of di-calcium phosphateas a carrier. This is not indicated in the tables for the sake ofsimplification. The laboratory tests were performed on amounts of freshmilled flour such that the treatments corresponded to the use of aboutounce of the compositions per 196 pound barrel of flour.

TABLE I Blend of hard and soft wheat flour Loaf Crumb volume colorTexture Untreated 582 92 95 Mill treated nitrogen trichloridc andbenzoyl peroxidm 602 98 98 Laboratory treated 45 gm. benzoyl peroxideand 6 gm. potassium bromate. 625 99 99 Laboratory treated 45 gm. benzoylperoxide and 12 gm. potassium bromate 630 99 99 Laboratory treated 45gm. benzoyl perox e 538 07 95 Laboratory treated 45 gm. benzoyl peroxidegm. sodium chlorate 560 97 95 TABLE H H wrd wheat baker flour Loafvolume Texture c. c. 0 or Untreated 598 92 95 Mill treated nitrogentrichloride and benzoyl peroxide 681 97 98 Laboratory treated 45 gm.benzoyl peroxide and 6 gm. potassium bromate... 738 99 99 Laboratorytreated 45 gm. benzoyl peroxide and 12 gm. potassium bromate. 763 99 99Laboratory treated 45 gm. benzoyl peroxide 560 95 95 Laboratory treated45 gm. benzoyl peroxide and 20 gm. sodium chlorate 580 95 95 It will beobserved from these tables that with the compositions of this inventionthere was obtained about twice as much improvement as with the two-stagenitrogen trlchloride, benzoyl peroxide method now in general use forbleaching and ageing flour. It will also be noted that no maturing wasobtained with a composition containing as much as 20 parts sodiumchlorate to 45 parts benzoyl peroxide.

In the appended claims, I have characterized the peroxides as active andas having substantial flour bleaching properties in order to distinguishfrom those aromatic and fatty acid peroxides, such as phthalyl peroxide,which are of insufficient activity and bleaching power to effect acommercial bleach. By substantial flour bleaching properties is meantthe ability to bleach flour satisfactorily for commercial purposes, thatis, to effect at least a 90% bleach. The inorganic peroxides and theorganic peroxides not of aromatic or fatty acid derivation are entirelytoo inactive for use with the bromates in accordance with thisinvention.

Having described my invention, I claim:

1. A method for improving wheat flour and other milling products whichcomprises intifor a sufilcient time to bleach and mature the matelymixing with the dry milling product a. powdered bromate and a powderedactive organic peroxide selected from the group consisting of thearomatic and fatty acid peroxides having substantial flour bleachingproperties, and subjecting the milling product in dry form to thesimultaneous action of the bromate and peroxide for a suflicient time tobleach and mature the product.

2. A method for improvin wheat flour and other milling products whichcomprises intimately mixing with the dry milling product a powderedbromate and a powdered active aromatic peroxide having'substantial flourbleaching properties, and subjecting the milling product in dry form tothe simultaneous action of the bromate and peroxide for a sufficienttime to bleach and mature the product.

3. A method for improving wheat flour and other milling products whichcomprises intimately mixing with the dry milling product a. powderedbromate and a powdered active fatty acid peroxide having substantialflour bleaching properties, and subjecting the milling product in dryform to the simultaneous action of the bromate and peroxide for asuflicient time to bleach and mature the product.

4. A method for improving wheat flour and other milling products whichcomprises intimately mixing powdered benzoyl peroxide and a powderedbromate with the dry milling product and subjecting the latter in-dryform to the simultaneous action of the peroxide and bromate millingproduct.

5. A method for improving wheat flour and other milling products whichcomprises intimately mixing powdered benzoyl peroxide and potassiumbromate with the dry milling product and subjecting the later in dryform to the simultaneous action of the peroxide and bromate for asuflicient time to bleach and mature the milling product.

6. A flour bleaching and ageing composition comprising a dry,free-flowing powdered mixture of a bromate and an active organicperoxide selected from the group consisting of the arcmatic and fattyacid peroxides having substantial flour bleaching properties.

7. A flour bleaching and ageing composition comprising a dry;free-flowing powdered mixture of a bromate and an active aromaticperoxide having substantial flour bleaching properties.

8. A flour bleaching and ageing composition comprising a dry,free-flowing powdered mixture of a bromate and an active fatty acidperoxide having substantial flour bleaching properties.

9. A flour bleaching and maturing composition comprising a dry,free-flowing powdered mixture of benzoyl peroxide and a bromate.

0. A flour bleaching and maturing composition comprising a dry,free-flowing powdered mixture of benzoyl peroxide and potassium bromate.

FREDERIC H. PENN.

